This invention relates to electrical connectors, and particularly to low inductance, high-speed electrical connectors for attachment of electrical signal transmission cables to printed circuit boards.
Conductors carrying high frequency signals and currents are subject to interference and cross talk when placed in close proximity to other conductors carrying high frequency signals and currents. This interference and cross talk can result in signal degradation and errors in signal reception. Shielded cables are available to carry signals from a transmission point to a reception point, and reduce the likelihood that the signal carried in one shielded or coaxial cable will interfere with the signal carried by another shielded or coaxial cable in close proximity. However, at points of connection, such as connection to a printed circuit board, the shielding for the signal is often lost, thereby allowing interference and crosstalk between signals. The use of individual shielded wires and cables is often not desirable at points of connection due to the need for making a large number of connections in a very small space. In these circumstances, two-part high-speed electrical connectors containing shielded conductive paths are used.
In high-speed electrical connectors containing shielded conductive paths, it is desirable to provide a stable impedance profile for each of the signal conductors in the connector. Instabilities in the impedance profile will introduce undesirable distortions in the transmitted signal, and a stable impedance profile becomes of increasing importance as frequencies and currents increase. Instabilities in the impedance profile may result from, for example, failure of a ground path associated with a signal conductor, or an insufficient ground path between two signal conductors. A high-speed electrical connector having improved reliability of shielding for high frequency signals and currents is needed.